package com.ihr360.job.core.step.skip;

import org.springframework.classify.Classifier;
import org.springframework.classify.SubclassClassifier;

import java.util.Map;

/**
 * A {@link SkipPolicy} that depends on an exception classifier to make its
 * decision, and then delegates to the classifier result.
 *
 * @author Dave Syer
 *
 * @see SubclassClassifier
 */
public class ExceptionClassifierSkipPolicy implements SkipPolicy {

    private SubclassClassifier<Throwable, SkipPolicy> classifier;

    /**
     * The classifier that will be used to choose a delegate policy.
     *
     * @param classifier the classifier to use to choose a delegate policy
     */
    public void setExceptionClassifier(SubclassClassifier<Throwable, SkipPolicy> classifier) {
        this.classifier = classifier;
    }

    /**
     * Setter for policy map. This property should not be changed dynamically -
     * set it once, e.g. in configuration, and then don't change it during a
     * running application. Either this property or the exception classifier
     * directly should be set, but not both.
     *
     * @param policyMap a map of String to {@link SkipPolicy} that will be used
     * to create a {@link Classifier} to locate a policy.
     */
    public void setPolicyMap(Map<Class<? extends Throwable>, SkipPolicy> policyMap) {
        SubclassClassifier<Throwable, SkipPolicy> subclassClassifier = new SubclassClassifier<Throwable, SkipPolicy>(
                policyMap, new NeverSkipItemSkipPolicy());
        this.classifier = subclassClassifier;
    }

    /**
     * Consult the classifier and find a delegate policy, and then use that to
     * determine the outcome.
     *
     * @param t the throwable to consider
     * @param skipCount the current skip count
     * @return true if the exception can be skipped
     * @throws SkipLimitExceededException if a limit is exceeded
     */
    @Override
    public boolean shouldSkip(Throwable t, int skipCount) throws SkipLimitExceededException {
        return classifier.classify(t).shouldSkip(t, skipCount);
    }

}
